1. Field of the Invention
The present invention relates to a system and method for directing heating and cooling air from an air handler to various zones in a home or commercial structure.
2. Description of the Related Art
Most traditional home heating and cooling systems have one centrally-located thermostat that controls the temperature of the entire house. The thermostat turns the Heating, Ventilating, and Air-Conditioner (HVAC) system on or off for the entire house. The only way the occupants can control the amount of HVAC air to each room is to manually open and close the register vents throughout the house.
Zoned HVAC systems are common in commercial structures, and zoned systems have been making inroads into the home market. In a zoned system, sensors in each room or group of rooms, or zones, monitor the temperature. The sensors can detect where and when heated or cooled air is needed. The sensors send information to a central controller that activates the zoning system, adjusting motorized dampers in the ductwork and sending conditioned air only to the zone in which it is needed. A zoned system adapts to changing conditions in one area without affecting other areas. For example, many two-story houses are zoned by floor. Because heat rises, the second floor usually requires more cooling in the summer and less heating in the winter than the first floor. A non-zoned system cannot completely accommodate this seasonal variation. Zoning, however, can reduce the wide variations in temperature between floors by supplying heating or cooling only to the space that needs it.
A zoned system allows more control over the indoor environment because the occupants can decide which areas to heat or cool and when. With a zoned system, the occupants can program each specific zone to be active or inactive depending on their needs. For example, the occupants can set the bedrooms to be inactive during the day while the kitchen and living areas are active.
A properly zoned system can be up to 30 percent more efficient than a non-zoned system. A zoned system supplies warm or cool air only to those areas that require it. Thus, less energy is wasted heating and cooling spaces that are not being used.
In addition, a zoned system can sometimes allow the installation of smaller capacity equipment without compromising comfort. This reduces energy consumption by reducing wasted capacity.
Unfortunately, the equipment currently used in a zoned system is relatively expensive. Moreover, installing a zoned HVAC system, or retrofitting an existing system, is far beyond the capabilities of most homeowners. Unless the homeowner has specialized training, it is necessary to hire a specially-trained professional HVAC technician to configure and install the system. This makes zoned HVAC systems expensive to purchase and install. The cost of installation is such that even though the zoned system is more efficient, the payback period on such systems is many years. Such expense has severely limited the growth of zoned HVAC systems in the general home market.